@book{PPN593808231, title = {Geometrie der Ebene Bd. 1, Th.1}, series = {GDML\_Books}, publisher = {Teubner}, address = {Leipzig}, year = {1875}, language = {de}, url = {http://dml.mathdoc.fr/item/PPN593808231} }
Clebsch, Alfred. Geometrie der Ebene Bd. 1, Th.1. GDML_Books (1875), http://gdmltest.u-ga.fr/item/PPN593808231/